base58.c

#include <stdio.h>
#include <string.h>

#define BASE58_DECODE_BASE 0
#define BASE58_ENCODE_BASE 0
#define BASE58_DECODE_OUT_OF_RANGE 1

void print_array(unsigned char* arr, int len){
	int i = 0;
	for (i=0; i<len; ++i){
		printf("%02X ",arr[i]);
	}
	printf("\n");
}

static unsigned char alphabet[] = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz";

int base58Encode(const char* input,const unsigned int inLen,unsigned char *output,unsigned int outLen)
{
	int i,j,tmp;
	memset(output,0,outLen);
	for(i=0;i<inLen;i++)
	{
		unsigned int c = input[i] & (0xff) ;
		for(j=outLen-1;j>=0;j--)
		{
			tmp = output[j] * 256 + c;
			c = tmp/58;
			output[j] = tmp%58;
		}
	}
	for(j=0; j<outLen; ++j)
	{
		output[j] = alphabet[output[j]];
	}
	return BASE58_ENCODE_BASE;
}




int base58Decode(const char* addr,const unsigned int addrLen,unsigned char *buf,unsigned int bufLen)
{
	int i,j;
	unsigned int tmp;
	memset(buf,0,bufLen);
	for(i=0;i<addrLen;i++)
	{
		unsigned int c = addr[i];

		if (addr[i] < 58){ // Numbers
			c -= 49;
		}else if (addr[i] < 73){ // A-H
			c -= 56;
		}else if (addr[i] < 79){ // J-N
			c -= 57;
		}else if (addr[i] < 91){ // P-Z
			c -= 58;
		}else if (addr[i] < 108){ // a-k
			c -= 64;
		}else{ // m-z
			c -= 65;
		}

		for(j=bufLen-1;j>=0;j--)
		{
			tmp = buf[j] * 58 + c;
			c = (tmp & (~0xff)) >> 8;
			buf[j] = tmp & (0xff);
		}
	}

	return BASE58_DECODE_BASE;
}
int main()
{
	//char addr[]="1NQEQ7fkCQQiVKDohBGuE3zSYs7xfDobbg";
	char addr[]="111";
	//char addr[]="5R1";
	//char addr[]="113YAvwi1V9WV9GEykK6XQ1UypmFPhVyh1";
	const int addrLen = 3;
	//char addr[]="115R";
	//const int addrLen = 4;
	const int bufLen = 25;
	char buf[bufLen];
	char addr2[addrLen];
	memset(buf,0,bufLen);
	print_array(addr,addrLen);
	base58Decode(addr, addrLen, buf, bufLen);
	print_array(buf,bufLen);
	base58Encode(buf, bufLen, addr2, addrLen);
	print_array(addr2,addrLen);

	return 0;
}